Search

Anomaly detection is automatic identification of the abnormal behaviors embedded in a large amount of normal data. This paper presents a method based on one class support vector machine (OCSVM) for detecting network anomalies. The telecommunication network performance data are used for the investigation. Firstly, the raw data are preprocessed in order to produce the vector sets required by the OCSVM algorithm. After preprocessing, the vector set of the training data is used to train the OCSVM detector, which is capable of learning the nominal behaviors of the data. The trained detector is then applied on the test data to detect the anomalies. The detected anomalies are finally categorized into major or minor level by comparing with a threshold. In this paper, experiments on three different types of performance data are presented and the results demonstrate the promising performance of the algorithm. [ABSTRACT FROM AUTHOR]

An ad hoc network (MANET) has no fixed networking infrastructure, and consists of mobile nodes that communicate with each other. Since nodes are mobile, Routing in ad hoc network is a challenging task. Efficient routing protocols can make better performance in such networks. Many protocols have been proposed for ad hoc networks which the most common types are: Ad hoc on-demand Distance Vector (AODV), Dynamic Source Routing (DSR), Optimized Link State Routing (OLSR). In this paper, we introduce a new Position and Neighborhood based Routing (PNR) algorithm for mobile ad hoc networks which uses GPS and new algorithm to reduce the overhead caused by position update messages. We also compare our scheme with DSR, AODV, OLSR for two metrics: packet delivery ratio and end-to-end delay. We use GlomoSim [1] to evaluate these protocols. [ABSTRACT FROM AUTHOR]

Given a finite set P of n points in d-dimensional Euclidean space, the diameter is defined as the maximum Euclidean distance between any two points in the set P. In this paper, we illustrate a time-optimal algorithm to compute the diameter of a point set on a theoretical network called a completely overlapping network (CON). This network model has an applicable potential in real-life applications because it is an extension of LANs that are widely used at present. [ABSTRACT FROM AUTHOR]

Finding association rules is one of the most investigated fields of data mining. Computation and communication are two important factors in distributed association rule mining. In this problem Association rules are generated by first mining of frequent itemsets in distributed data. In this paper we proposed a new distributed trie-based algorithm (DTFIM) to find frequent itemsets. This algorithm is proposed for a multi-computer environment. In second phase we added an idea from FDM algorithm for candidate generation step. Experimental evaluations on different sort of distributed data show the effect of using this algorithm and adopted techniques. [ABSTRACT FROM AUTHOR]

Maintenance of the cache consistency is a complicated issue in the wireless mobile environment. Caching of frequently accessed data items on the node can reduce the bandwidth requirement of the mobile node environment. In this paper, we present a new technique called Modified Energy Efficient Cache Invalidation Algorithm (MEECIA) especially to reduce the uplink bandwidth consumption in the wireless ad-hoc network, by choosing following modes: Slow, Fast, Super-fast. The mode is selected based on threshold specified for time and the number of node requesting the updated data to other node. Simulation results demonstrate that our algorithm is efficient in improving mobile caching, reducing the communication bandwidth and also efficiently utilizing the energy in ad-hoc network. Compared to the previously reported cache based Invalidation Report (IR), our scheme can significantly improve the performance in terms of energy consumption and reduce the query latency in ad-hoc network. [ABSTRACT FROM AUTHOR]

In this paper we propose an approach to improve the performance of existing flood based routing algorithm Ad-hoc on demand Distance Vector Routing [2] for mobile Ad-hoc wireless networks based on heuristic searching technique. Flooding technique is often used for route discovery in on demand mechanism in MANET such as AODV, DSR. To avoid the problem of wireless broadcast storm, the heuristic searching approach was introduced in the process of finding route from source node to destination node. Heuristic function considers the characteristics of MANET (Bandwidth, number of nodes in the given range). If a node S wants to send a packet to D in the flooding method S sends packet to all its neighbor nodes, but in the proposed scheme tries to reduce broadcasting by finding heuristic measures of the neighbors of S. The heuristic measures are evaluated by applying a function to all neighbors. [ABSTRACT FROM AUTHOR]

This paper proposes a new discrete-time queue analytical model based on BLUE algorithm in order to determine the network congestion in preliminary stages. We compare the original BLUE, which has been implemented in Java, with our proposed analytical model with regards to different performance measures (average queue length, throughput, average queueing delay and packet loss probability). The comparison results show that the proposed discrete-time queue analytical model outperforms BLUE algorithm in terms of throughput and packet loss probability. Moreover, the proposed model maintains the throughput performance regardless whether the amount of the traffic load is light or heavy. Furthermore, we calculate the packet dropping probability function for our analytical model and the BLUE algorithm in order to decide which algorithm drops fewer packets. [ABSTRACT FROM AUTHOR]

Crossbars are main components of communication switches used to construct interconnection networks. Scheduling algorithm controls contention in switch architecture. Several scheduling algorithms were proposed for input-queued crossbar switch architectures. This paper suggests a Dynamic Scheduling Algorithm (DSA). This algorithm changes the priority rotation dynamically based on two parameters: queue occupancy and quality of service of input and output. DSA efficiently utilizes the buffers and at the same time gives good service to the selected inputs and outputs. The simulation results show that DSA saves loss of the cells due to buffer overflow and thus increases the throughput by 2% to 4% compared to its counter part. DSA reduces the latency for prescribed Quality of Service class input output and increases the average latency. [ABSTRACT FROM AUTHOR]

Cartesian Ad hoc Routing Protocols (CARP) are a set of three adaptive and connectionless protocols that address the problem of routing and power consumption in MANET. These protocols are used to limit the number of forwarding nodes in a logical transmission area. Density of an ad hoc network considered a network parameter in CARP, and is used in the calculations to form a logical transmission area. The CARP assume that the nodes have some knowledge about the density from previous activity the network, but no specific density determining mechanism has been described. This research paper presents a density determining mechanism based on traffic monitoring. The CARP, many of the other ad hoc protocols, geneate a great deal of traffic for implementing some form of flooding, and this traffic can be exploited to deternibe density. The nodes in a network with implementation of CARP can use this density value to form the logical broadcast area. As the nodes in MANET are potentially in motion, density may change over time. The proposed algorithm also tracks the density value over time and keeps it updated as per situation of the network. The simulation results in OPNET Modeler 10.5 validate the performance of this density determining algorithm for CARP. [ABSTRACT FROM AUTHOR]

This paper proposes a framework for generating sizing function in meshing assemblies. Size control is crucial in obtaining a high-quality mesh with a reduced number of elements, which decreases computational time and memory use during mesh generation and analysis. This proposed framework is capable of generating a sizing function based on geometric and non-geometric factors that influence mesh size. The framework consists of a background octree grid for storing the sizing function, a set of source entities for providing sizing information based on geometric and non-geometric factors, and an interpolation module for calculating the sizing on the background octree grid using the source entities. Source entities are generated by performing a detailed systematic study to identify all the geometric factors of an assembly. Disconnected skeletons are extracted and used as tools to measure 3D-proximity and 2D-proximity, which are two of the geometric factors. Non-geometric factors such as user-defined size and pre-meshed entities that influence size are also addressed. The framework is effective in generating a variety of meshes of industry models with less computational cost. [ABSTRACT FROM AUTHOR]

Chapter 5 gives an overview of algorithms and lower bounds for channel assignment problems in cellular networks, when adjacent and inter-site channel interference are considered in addition to co-channel interference. It also discusses relevant results on graph labelling, which forms the basis of many of the algorithms. [ABSTRACT FROM PUBLISHER]

Chapter 11 surveys wireless data broadcast (or broadcast scheduling) algorithms. Base stations or satellites broadcast data simultaneously to all users. Each user has a list of desired files it wants to receive from the server. The order and frequency for each file or datum that is broadcast should take access efficiency and power conservation into account. [ABSTRACT FROM PUBLISHER]

Chapter 8 identifies key issues in wireless fair queuing, defines a wireless fair service model, and surveys algorithms. Fairness implies that the allocated channel bandwidth is in proportion to the "weights" of the users. Wireless fair queuing poses significant challenges due to location-dependent and bursty channel errors in the wireless channel. [ABSTRACT FROM PUBLISHER]

Considers the problem of mapping a parallel application onto a transputer network consisting of transputers and crossbars with no inter-crossbar links. Methodology of the mapping of a process graph onto a fixed interconnection network; Factors that constraint the mapping; Algorithm used in embedding the guest graph into the system.

Describes the parallel implementation of a divide-and conquer template which is derived systematically from its functional specification. Discussion on divide-and-conquer algorithms; Introduction of the generic specification of divide-and-conquer; Use of the N-graphs for parallel implementation of divide-and-conquer; Parallelization of divide-and-conquer using formal transformations in the Bird-Meertens formalism.